Synthesis of tripeptide using Merrifield peptide synthesis procedure - Inclusion of asparagine

I am supposed to synthesize tripeptide, $$\mathrm{Ala-Asn-Phe}$$, using Merrifield peptide synthesis procedure. Accordingly, I have done followings:

1. Attached protected $$\mathrm{Phe}$$ as the first amino acid.
2. Got rid of protecting group ($$\mathrm{BOC}$$)
3. Added asparagine with 2 protecting groups - $$\mathrm{BOC}$$ for $$\alpha$$-$$\ce{NH2}$$ group and $$\mathrm{FMOC}$$ for the $$\gamma$$-$$\ce{NH2}$$ group.
4. Got rid of $$\mathrm{BOC}$$ and added $$\mathrm{Ala}$$ protected with $$\mathrm{BOC}$$.
5. Got rid of $$\mathrm{BOC}$$ and $$\mathrm{FMOC}$$, and used $$\ce{HF}$$ to release the peptide.

Is this going to work? The thing that worries me the most is the $$\gamma$$-amino group and using $$\mathrm{FMOC}$$ - is that a good idea?

• Are you following a known protocol for solid-state synthesis? My question is because I wonder why you have to protect amide $\ce{NH2}$. Look, when you get asparagine attached to phenylalanine, you got anothe peptide (amide) bond with $\ce{NH}$ bond, but you didn't care to protect that. – Mathew Mahindaratne Nov 27 '19 at 0:06
• @MathewMahindaratne well NH from peptide bond will not react with -COOH group of alanine that I am adding next... Or am I mistaken? – Geek Nov 27 '19 at 0:29
• My point is it's not necessary to protect amide $\ce{CONH2}$ group. It is not competitive enough with readily available $\alpha$-$\ce{NH2}$ group for DCC coupling. – Mathew Mahindaratne Nov 27 '19 at 0:46
• I agree, primary amides are not strong nucleophiles so it is not necessary to protect the Asparagine amide. I presume you are using coupling agents to attach the Asparagine and Alanine – Waylander Nov 27 '19 at 8:12
• You just don't need the FMOC at all. – Beerhunter Nov 27 '19 at 17:11